chore: remove vtubers as builitin

[ker0olos]

• moving vtubers to be hosted on https://packs.deno.dev
  • removed vtubers from the builtin list instead it will be a normal pack that is just installed by default and can be removed like any other community pack

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 85.71429% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 80.29%. Comparing base (b2e5ca8) to head (d30e7e9).

Files	Patch %	Lines
src/packs.ts	75.00%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #368 +/- ## ========================================== - Coverage 80.74% 80.29% -0.45% ========================================== Files 43 43 Lines 12059 11639 -420 Branches 1369 1363 -6 ========================================== - Hits 9737 9346 -391 + Misses 2299 2270 -29 Partials 23 23 ```

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